I love this, from the selection I picked the Sharp filter. Using this makes all my GBA/DS games look way better. If you see this, I noticed that the brightness jumps up and down while playing Osu! 2 or Sonic advance. Haven't tried it on other games yet, but I love it.
- you have power saving mode on
- I don't compensate in the LCD controller for the altered widescreen viewport, meaning that the wide edges will not count towards the total brightness seen by the LCD controller, and so the brightness may change unpredictably, as the LCD controller is only seeing the middle unstretched part